Conventionally, technologies have been proposed which allow a user to enter a size condition in order to search for a product with a size desired by the user. For example, Patent Literature 1 to be mentioned later discloses a product search for system that allows a user to directly enter values of a width, a depth, and a height of a product, and searches for a product matching such width, depth, and height.
Conversely, technologies have been conventionally proposed which detect a position of each joint of the body of a human. For example, Patent Literature 2 to be mentioned later discloses a technology of detecting a gesture obtained when a human takes predetermined still posture and motion through a camera which can detect a depth, and enters various kinds of instructions.